1. Field of the Invention
The present invention relates to an apparatus and a method for controlling image display and, more particularly to an image display controller and an image display control method arranged to display one frame of image in a restricted display area (window) so that the entire image can be looked over.
2. Description of the Related Art
FIG. 26 is a diagram of the relationship between an image data area defined as the entire area of one frame of image and a display area of a window in which the image is displayed in a conventional manner. If the image data area is larger than the display area, only a portion of the image data area is displayed, as illustrated in FIG. 26.
FIG. 27 is an example of a display made in this manner. A window 2 is displayed on a display screen 1, and predetermined letters are displayed in the window 2. In the case of display illustrated in FIG. 27, a partial displayed area in the image data area shown in FIG. 26 is cut out to be displayed in the window 2 since the entire image data area cannot be displayed in the window 2.
In the case of display illustrated in FIG. 27, while a portion of one frame of image is displayed in the window 2 having a restricted size, scroll bar areas 4 and 7 are provided in right and lower end portions of the window 2 and bars having lengths corresponding to the display area are displayed in the bar areas 4 and 7 to enable the presently-displayed area to be intuitively recognized. In the example illustrated in FIG. 27, the length of each of the hatched areas indicates the range in which part of the area of one frame of image is displayed in the window 2.
An up button 5 and a down button 6 are provided respectively at the upper and lower ends of the scroll bar area 4 while a left button 8 and a light button 9 are provided respectively at the left and right ends of the scroll bar 7. Each of these buttons is pointed at with a cursor and operated through the operation of a mouse or the like to scroll the displayed area in the vertical or horizontal direction.
FIG. 28 shows an example of a display of one frame (one page) of image of A4 size in window 2. In this example, as illustrated, only an upper portion of the A4 image is displayed while the other portion close to the lower side is cut and undisplayed.
As described above, when one frame of image is displayed by a conventional display apparatus, only a portion of the image is displayed and the displayed area is scrolled if it is necessary to see the other portion of the image. The position of the actually displayed area in the entire image is indicated by the scroll bars.
However, the scroll bars are provided in very narrow areas in the vicinity of the ends of the window, so that it is difficult to speedily and correctly recognize the entire area from which the displayed area is selected.
In the case of display illustrated in FIG. 28, the image is displayed so that, in its lower position, continuous lines end at the lower end of the window. In this situation, it can easily be understood that a certain image portion is undisplayed as if it is hidden below the end of the window. However, in a situation where no image portion ends at this end of the window, the existence of the undisplayed area below this position may be overlooked. In searching a predetermined article or the like displayed in a similar manner, therefore, the possibility of missing a target is not negligible.